As methods for introducing cross-linkable groups into isobutylene-based polymers, Patent Literatures 1 to 4 describe methods for introducing cross-linkable silicon groups into isobutylene-based polymers. Patent Literatures 5 to 7 also describe methods which involve introducing unsaturated groups into ends of polyisobutylenes. In addition, Patent Literature 8 describes a method which involves copolymerizing isobutylene with a non-conjugated diene such as 1,9-decadiene.
Patent Literatures 9 and 10 describe alicyclic vinyl ether polymers.